1. Field of the Invention
The present invention relates to a holder for a wire coil having spring-loaded prongs which press against the inside of a coil.
2. Description of the Prior Art
Electricians have wrestled with electrical wire coils virtually since the day wire was first manufactured. These coils, while being both heavy and bulky, must be unwound with care lest the wire twist or kink. Such careful handling, while necessarily frustrating and time-consuming, is mandated by proper wiring procedure.
As an example, copper wire which has become twisted is readily susceptible to fatigue failure during further handling. However, a small gap in the metal will initially be unnoticed, because the wire is usually sheathed with a plastic wrapping. Unfortunately, once the circuit is energized, arcing may occur at the gap, creating a hazardous condition. Consequently, such wire must then be identified and replaced, thereby increasing labor and material costs accordingly.
It has been suggested in the past to mount wire coils on a reel having a plurality of radially adjustable prongs or "fingers", as illustrated in U.S. Pat. Nos. 524,657 and 502,373. However, the fingers are manually secured in position by pins or bolts.
Other wire reels have also been proposed which utilize linkage interconnecting the fingers for radial movement, as seen in U.S. Pat. Nos. 3,931,941 and 1,147,680. These reels have generally proven to be unsatisfactory because the linkages are necessarily exposed, and subject to accidental bending and also to entanglement with the loose end of a wire coil.
The above disadvantages are noticeably amplified at most job sites. Typically, the electrician attaches the coil to a reel which feeds the cable to an adjacent device to measure, straighten and cut the wire. However, in practice, a wide variety of wire sizes are usually specified, and the electrician is forced to often remove the wire from the reel and replace it with a coil of a different size. In such cases, the speed at which the electrician can change the coils becomes critical.
As a result, there remains a decided need in the art for an electrical cable reel which can be simply operated to allow fast changeover of coils, yet be highly effective for a wide variety of wire thicknesses and coil sizes.